It is written as an abi break, but could be rewritten to not require one with some care (at least binary compatible, technically source compatibility breaks and theoretically its still a behavior change). I just decided against it at the time it was clear we would have to keep the diversion a little longer than originally planed and backported just the "absolutely needed" stuff. We could do it now, but I guess the time is better spent in stopping to semi-maintain two branches. Hence setting "fix commited" in anticipation of "fix released" soon [all while realizing that I might very well be the biggest blocker in this process with my perfectionism]